Recovery from neuromuscular blockade after either bolus and prolonged infusions of cisatracurium or rocuronium using either isoflurane or propofol-based anesthetics

We examined the recovery characteristics of cisatracurium or rocuronium after bolus or prolonged infusion under either isoflurane or propofol anesthesia. Sixty patients undergoing neurosurgical procedures of at least 5 h were randomized to receive either isoflurane with fentanyl (Groups 1 and 2) or propofol and fentanyl (Groups 3 and 4) as their anesthetic. Groups 1 and 3 received cisatracurium 0.2 mg/kg IV bolus, spontaneously recovered, after which time an infusion was begun. Groups 2 and 4 received rocuronium 0.6 mg/kg IV, spontaneously recovered, and an infusion was begun. Before the end of surgery, the infusion was stopped and recovery of first twitch (T(1)), recovery index, clinical duration, and train-of-four (TOF) recovery was recorded and compared among groups by using appropriate statistical methods. Clinical duration was shorter for rocuronium compared with cisatracurium using either anesthetic. Cisatracurium T(1) 75% recovery after the infusion was shorter with propofol compared with isoflurane. Cisatracurium TOF 75% recovery was similar after either bolus or infusion, but rocuronium TOF 75% recovery after the infusion was delayed. Infusion rates decreased for cisatracurium but remained relatively constant for rocuronium regardless of the anesthetic used. Isoflurane enhances the effect of both muscle relaxants but prolonged cisatracurium recovery more than rocuronium. Of the two muscle relaxants studied, rocuronium's recovery was most affected by length of the infusion. Cisatracurium may be a more desired muscle relaxant for prolonged procedures because recovery was least affected by prolonged infusion. Implications: This study describes the effect of different anesthetic techniques on the recovery of two different muscle relaxants, cisatracurium and rocuronium, when administered as either a single bolus or prolonged infusion during neurosurgery. This study demonstrates the feasibility of using these relaxants for these prolonged procedures.     

The effect of cisatracurium and rocuronium on cisatracurium precurarization and the priming principle

STUDY OBJECTIVE: To demonstrate the effect of administering a precurarizing dose of cisatracurium or rocuronium on the speed of onset of cisatracurium, and to review the possible mechanisms and value of the priming principle. DESIGN: Double-blind, randomized, controlled trial. SETTING: Inpatient anesthesia in a university teaching hospital. PATIENTS: 90 ASA physical status I and II patients undergoing elective surgery requiring endotracheal intubation. INTERVENTIONS: Three groups of 30 patients each were investigated. Following induction of anesthesia with fentanyl and propofol, Group 1 received cisatracurium 0.015 mg.k(-1), Group 2 received rocuronium 0.09 mg. kg(-1), and Group 3 (control) received normal saline. Six minutes after priming, Groups 1 and 2 received cisatracurium 0.135 mg. kg(-1) whereas Group 3 received cisatracurium 0.15 mg. kg(-1). MEASUREMENTS AND MAIN RESULTS: In each group, first twitch height and the train-of-four ratios were recorded every 10 seconds after the initial priming dose. Intubation was attempted after the first twitch height became less than 15% of baseline. The decrease in the train-of-four ratios at 6 minutes was 0.97 for cisatracurium and 0.85 for rocuronium. The onset of muscle relaxation was significantly faster after priming with cisatracurium and rocuronium (71.7 +/- 21.3 and 65 +/- 19.8 sec, respectively) compared with control (148.7 +/- 43.1 sec). Females receiving both muscle relaxants had a faster onset of paralysis than did males (65.9 +/- 20.6 vs. 79.2 +/- 20.6 and 55 +/- 14.5 vs. 71.7 +/- 20.4 sec). Intubation conditions were either excellent or satisfactory in all patients. CONCLUSIONS: Six minutes after precurarization, there is no significant difference between rocuronium and cisatracurium when used as priming drugs. An even faster onset time with both drugs was demonstrated in females. The use of priming doses of 25% to 30% of ED(95) may cause symptomatic muscle weakness. The mechanisms of the priming principle are discussed.     

Cisatracurium am M. orbicularis oculi Vergleich der neuromuskulären Wirkung von Cisatracurium und Atracurium am M. orbicularis oculi und M. adductor pollicis

OBJECTIVES: Muscle relaxants have different pharmacodynamic profiles in various muscles. Therefore, results obtained for one muscle cannot be extrapolated to other muscles. In the adductor pollicis muscle cisatracurium exerts a pharmacodynamic profile comparable to atracurium, despite the known difference in onset time. However, studies evaluating the neuromuscular effect of cisatracurium in different muscles are lacking. Accordingly, this study compares the pharmacodynamic profile of cisatracurium and atracurium in the orbicularis oculi muscle (OO) - which shows a neuromuscular course similar to the diaphragm and the laryngeal muscles - and the adductor pollicis muscle (AP). METHODS: Forty-five patients (ASA I-II), scheduled for elective spinal surgery were anaesthetized with propofol and fentanyl. Endotracheal intubation was performed without using a muscle relaxant. Neuromuscular transmission was monitored using acceleromyography in both muscles. Patients received 0.1 mg/kg (2x ED(95)) or 0.15 mg/kg (3x ED(95)) cisatracurium, or 0.5 mg/kg atracurium (2x ED(95)) at random. Onset and recovery times were measured according to the recommendation of the Copenhagen Consensus Conference. RESULTS: Onset time was significantly shorter in the OO than in the AP following 0.15 mg/kg cisatracurium and 0.5 mg/kg atracurium (P<0.05). No differences in onset time between the two muscles were found after 0.1 mg/kg cisatracurium. The recovery of T(1) to 10% of its control was completed sooner in the OO than in the AP in all three groups (P<0.05). CONCLUSIONS: Cisatracurium shows a dose-dependent shorter onset time in the OO than in the AP. This is consistent with the current view that the onset of non-depolarizing neuromuscular blockers is more rapid in the OO than in the AP. However, at least a dose of 3x ED(95) of cisatracurium was necessary to show a difference in onset time between both muscles. In contrast, atracurium is reported to lead to a significantly shorter onset of neuromuscular block in the OO following 2x the ED(95). The more rapid recovery of T(1) to 10% of its control in all three groups in the OO is due to the relative resistance of this muscle to muscle relaxants.     

Effect of different doses of cisatracurium on intraocular pressure in sedated patients

BACKGROUND AND OBJECTIVE: The aim was to examine the course of intraocular pressure after relaxation with different doses of cisatracurium. METHODS: The investigation was carried out as a prospective, randomized double-blind study in a crossover design in 30 postoperative patients with stable haemodynamic and respiratory function (ASA I and II). To exclude any disrupting factors, patients remained intubated and continuously sedated. Twenty patients received an intubation dose (2 x ED95) of cisatracurium (0.1 mg kg(-1)) compared with atracurium (0.5 mg kg(-1)). In a second series, 10 patients were given an effective dose, ED95 (0.05 mg kg(-1)), and a repeat dose (0.02 mg kg(-1)) of cisatracurium. The intraocular pressure was determined before (T0) as well as 1 (T1), 5 (T5), 10 (T10), 15 (T15), 20 (T20) and 45 (T45) min after bolus administration. RESULTS: Intraocular pressure decreased after an intubation dose of either cisatracurium or atracurium, and reached a minimum after 10 min (6.7 +/- 2.2 and 7.9 +/- 2.1 mmHg, respectively). There was no significant difference between either muscle relaxant (P = 0.27). When lower doses of cisatracurium (0.05 and 0.02 mg kg(-1)) were applied, the intraocular pressure also decreased, albeit to a lesser extent and with a delayed onset (8.4 +/- 1.9 mmHg after 10 min, 9.9 +/- 3.4 mmHg after 15 min). There was no significant difference between dosages (p = 0.44). CONCLUSIONS: Cisatracurium is a useful drug in patients when a decrease of intraocular pressure is wanted and where muscle relaxation is necessary and acceptable.     

Large bolus dose vs. continuous infusion of cisatracurium during hypothermic cardiopulmonary bypass surgery

BACKGROUND AND OBJECTIVE: We investigated whether a high bolus dose of cisatracurium (8x ED95) given at induction can provide muscle relaxation for the major part of a cardiac procedure with hypothermic cardiopulmonary bypass, avoid important postoperative residual curarization and cause no waste of product. METHODS: Twenty patients were randomly assigned either to Group 1 (n = 10) or Group 2 (n = 10). Those in Group 1 were given cisatracurium in a high bolus dose (0.4 mg kg(-1)). Those in Group 2 received cisatracurium 0.1 mg kg(-1) at induction followed after 30 min by a continuous infusion of cisatracurium. As an escape medication in case of patient movement, a bolus dose of cisatracurium 0.03 mg kg(-1) was given. RESULTS: In Group 1 (large cisatracurium bolus dose), the clinical duration of effect (until T1/T0 = 25%) was 110 min. Six of 10 patients in Group 1 required additional boluses of cisatracurium intraoperatively. Four of these six had received an additional bolus near the end of surgery and had a train-of-four (TOF) ratio = 0 at the end. The other four patients in Group 1 had a final TOF ratio >0.9. In Group 2 (continuous cisatracurium infusion), only two patients had a TOF ratio >0.9 at the end of surgery, no patient moved and none received additional boluses. The total amount of cisatracurium used in the bolus and infusion Groups was 34.5 +/- 7.8 and 21.3 +/- 5.7 mg, respectively (P = 0.0004). CONCLUSIONS: For continued neuromuscular block during hypothermic cardiac surgery, a high bolus dose of cisatracurium appears to be safe, although it is not an alternative to a continuous infusion, as its neuromuscular blockade does not cover the intraoperative period and a high incidence of movements occurs. In the patients who received a high bolus dose of cisatracurium, postoperative residual curarization appeared after additional boluses had been given. The consumption of cisatracurium by high bolus was significantly greater than with continuous infusion.     

Neuromuscular blocking effects and train-of-four fade with cisatracurium: comparison with other nondepolarising relaxants

Neuromuscular blocking drugs exhibit different degrees of fade in response to train-of-four stimulation believed to represent their relative prejunctional effects. The present study was designed to compare the train-of-four fade after cisatracurium and compare this with other commonly used muscle relaxants. Train-of-four fade during onset and recovery of block were recorded after administration of cisatracurium 0.05 or 0.1 mg.kg-1, atracurium 0.5 mg.kg-1, vecuronium 0.08 mg.kg-1, mivacurium 0.15 mg.kg-1 or rocuronium 0.6 mg.kg-1 to patients anaesthetised with fentanyl, nitrous oxide and a propofol infusion. Neuromuscular monitoring was by stimulation of the ulnar nerve and recording the force of contraction of the adductor pollicis muscle. The onset and recovery of block were also measured. Train-of-four fade during onset of block was greater with the lower dose of cisatracurium compared with the higher dose of cisatracurium and all other relaxants. Train-of-four fade during recovery was similar. The median times (and ranges) for the onset of maximum block were 3.4 (2.1-5.6), 1.5 (1.2-2.3), 2.1 (1.2-2.6), 2.0 (1.5-2.7) and 1.0 (0.7-1.3) min for cisatracurium 0.1 mg.kg-1 and atracurium, mivacurium, vecuronium and rocuronium, respectively. The median times (and ranges) for the recovery of T1 to 25% of control and to a train-of-four ratio of 0.8 were 41 (21-50) and 65 (40-78); 43 (37-54) and 69 (58-79); 15 (11-20) and 25 (19-30); 31 (23-46) and 60 (45-117); and 33 (18-57) and 50 (28-76) min following cisatracurium, 0.1 mg.kg-1, atracurium, mivacurium, vecuronium and recuronium, respectively.     

Kardiovaskuläre Effekte nach Bolusapplikation von Cisatracurium

Cisatracurium – one of the ten stereoisomers of atracurium – is an intermediate long-acting non-depolarizing neuromuscular blocking agent. Cardiovascular reactions have been described after administration of cisatracurium or vecuronium in surgical patients. Methods. After approval by our institutional review board, 62 patients (ASA I–II) were randomly assigned to three groups to either receive 3×ED₉₅ or 5×ED₉₅ of cisatracurium or 3×ED₉₀ of vecuronium prior to intubation as a bolus. After oral premedication with 2?mg lormetazepam anaesthesia was induced with thiopental (4–12?mg/kg) and maintained with O₂/N₂O and isoflurane (1.5%–2%). Six minutes after administration of thiopental, patients received the muscle relaxant. Six minutes later 0.1–0.2?mg fentanyl was given and the trachea was intubated. Heart rate (HR) and blood pressure (BP) were monitored every minute. Changes of heart rate or blood pressure?>20% compared to baseline were defined as clinically significant. Results. After application of the study drug, median values of blood pressure and heart rate were stable. For each muscle relaxant, there were several patients who had statistically significant cardiovascular changes. After 3×ED₉₅ cisatracurium, 3 of 21 patients exhibited haemodynamic changes?>20% (2 exhibited hypotension and 1 tachycardia), while in the high-dose cisatracurium group 2 of 21 patients demonstrated a tachycardia that was predetermined to be statistically but not clinically significant. In the vecuronium group, 2 of 20 patients sustained statistically significant hypotension and 1 patient had statistically significant tachycardia. The frequency of all individual cardiovascular changes after the application of the muscle relaxant was not dose-dependent. Conclusion. After the administration of cisatracurium in two different doses (3×ED₉₅ and 5×ED₉₅) or vecuronium (3×ED₉₀) only minor cardiovascular changes were observed. Both drugs proved to be safe for use during induction of anaesthesia in patients ASA I–II. With regard to its cardiovascular effects, cisatracurium shares with vecuronium the requirements of an ideal muscle relaxant.     

Recovery from neuromuscular block after an intubation dose of cisatracurium and rocuronium in lumbar disc surgery

BACKGROUND AND OBJECTIVE: Residual muscle paralysis remains a concern for anaesthesiologists. This study investigated the recovery from neuromuscular block (NMB) after an intubation dose of cisatracurium (C) or rocuronium (R) in 32 patients undergoing lumbar disc surgery. METHODS: Anaesthesia was induced with propofol and sufentanil, and maintained with sevoflurane in nitrous oxide/oxygen. Patients were randomised to receive twice the ED95 of either cisatracurium (GC) or rocuronium (GR) before tracheal intubation. After placement in prone position, neuromuscular transmission was monitored at the wrist by accelerometry. NMB was antagonised when the TOF ratio (TOFR) was < 0.75 at muscle closure. The time from muscle relaxant to muscle closure, and to TOFR of 0.25 and of 0.50 were recorded. Data were analysed using Student's t-tests, chi-squared tests and two-way mixed-designed ANOVA's. The prediction probability (Pk) of the times from muscle relaxant to muscle closure, and to TOFR of 0.25 for the necessity to antagonize NMB was calculated in both groups. P < 0.05 was considered statistically significant. RESULTS: NMB was antagonized in 8 (GC) and 6 (GR) patients, respectively. The time from muscle relaxant to muscle closure was shorter in patients whose NMB was antagonized. The Pk of this time was significant in GC (0.85) but not in GR (0.69). In GR contrarily to GC, the times to a TOFR of 0.25 and 0.50 were longer in patients whose NMB was antagonized. The Pk of the time to TOFR of 0.25 was significant in GR (0.95) but not in GC (0.64). CONCLUSIONS: A single dose of cisatracurium or rocuronium may be associated to some degree of NMB at the end of lumbar surgery, depending on the duration of surgery and on the duration of action of the muscle relaxant which is more variable for rocuronium than for cisatracurium.     

Assessment of neuromuscular and haemodynamic effects of cisatracurium and vecuronium under sevoflurane-remifentanil anaesthesia in elderly patients

BACKGROUND AND OBJECTIVE: Neuromuscular block times, quality of muscle relaxation for tracheal tube insertion, and the haemodynamic effects after cisatracurium and vecuronium under sevoflurane-remifentanil anaesthesia were compared in elderly patients. METHODS: The study was performed in 40 patients over 65 yr of age. Anaesthesia was induced with thiopental, and maintained with sevoflurane in N2O/O2 and remifentanil. Cisatracurium 0.15 mg kg(-1) or vecuronium 0.1 mg kg(-1) were administered after induction. Intubation was attempted when neuromuscular block was 95%. Onset time, clinical duration of action, recovery index, spontaneous recovery time and tracheal intubation conditions were assessed. Haemodynamic parameters were also monitored. RESULTS: The average ages of the patients were 72.5 +/- 5.1 and 73.6 +/- 6.3 in the cisatracurium and vecuronium groups, respectively. Onset time was significantly shorter after vecuronium, 158 +/- 34 s vs. 200 +/- 50s, respectively. Recovery index was significantly shorter after cisatracurium, 19.5 +/- 7.5 s vs. 33.7 +/- 18.6 s (P < 0.05). Clinical duration and spontaneous recovery time were similar in both groups as well as haemodynamic variables. CONCLUSIONS: In elderly patients, vecuronium has a faster onset time while cisatracurium has a shorter recovery index under sevoflurane-remifentanil anaesthesia.     

Antagonism of cisatracurium and rocuronium block at a tactile train-of-four count of 2: should quantitative assessment of neuromuscular function be mandatory?

With a train-of-four (TOF) ratio >0.70 as the standard of acceptable recovery, postoperative residual paralysis is a frequent occurrence in postanesthesia care units (PACUs). However, detailed information regarding prior anesthetic management is rarely provided. We examined the incidence of postoperative weakness after the administration of cisatracurium and rocuronium when using a rigid protocol for muscle relaxant and subsequent neostigmine administration. Under desflurane, N(2)O, and opioid anesthesia, tracheal intubation was accomplished after either cisatracurium 0.15 mg/kg or rocuronium 0.60 mg/kg. The response of the thumb to ulnar nerve stimulation was estimated by palpation. Additional increments of muscle relaxant were given as needed to maintain the TOF count at 1 or 2. At the conclusion of surgery, at a TOF count of 2, neostigmine 0.05 mg/kg plus glycopyrrolate 10 micro g/kg was administered. The mechanical TOF response was then measured with a force transducer starting 5 min postreversal. Patients were observed until a TOF ratio of 0.90 was achieved. There were no significant differences in the recovery profiles of cisatracurium versus rocuronium. TOF ratios at 10 min postreversal were 0.72 +/- 0.10 and 0.76 +/- 0.11, respectively. At 15 min postreversal, only one subject in each group had a TOF ratio of <0.70. No patient in either group arrived in the PACU with a TOF ratio <0.70. Our results suggest that if cisatracurium or rocuronium is administered by using the TOF count as a guide, critical episodes of postoperative weakness in the PACU should be an infrequent occurrence. IMPLICATIONS: After the administration of cisatracurium or rocuronium, train-of-four (TOF) ratios <0.70 should rarely be observed in the postanesthesia care unit if neostigmine-assisted antagonism of residual block is delayed until the tactile TOF count at the thumb is 2 or more.     

不同肌松程度对脊柱手术皮层体感诱发电位的监测

目的：了解新型肌肉松弛药顺式阿曲库铵用于脊柱外科手术,肌松程度对皮层体感诱发电位（CSEP）监测的影响。方法：选择ASAI～II级,择期脊柱外科手术病人60例,随机分为6组。在首次推注插管剂量的顺式阿曲库铵后,连续监测T1,以肌松监测反馈调控输注模式调整不同剂量进行输注,维持各分组所要求的不同肌松程度,观察6组病例术中CSEP的P40波的波幅及潜伏期。同时对肌松分级进行主观评定。结果：在不同的肌松程度下,IV组、V组及VI组患者的波幅与基准值比较有统计学差异（P〈0.05）;I组、II组、III组患者的波幅与基准值比较无统计学差异（P〉0.05）。肌松主观评定,V组、VI组患者肌松评价差的例数与I组、II组、III组、IV组比较有统计学差义（P〈0.05）。结论：能满足CSEP监测的要求,同时也能满足手术及运动诱发电位监测需要的肌松程度是T1值在0～15%。     

The pharmacokinetics of cisatracurium in patients with acute respiratory distress syndrome

Continuous neuromuscular blockade is often necessary in patients being treated for acute respiratory distress syndrome (ARDS) to optimize oxygenation. In this study, neuromuscular blockade (no response to two responses at the train-of-four stimulation at the orbicularis oculi muscle) was achieved in six patients with ARDS by a continuous infusion of cisatracurium. The plasma concentration of cisatracurium during the infusion averaged 1.00 (0.25-1.45) microg/mL, expressed as median (range). The clearance and half-life were 6.5 (3.3-7.6) mL. min(-1). kg(-1) and 25 (16-48) min, respectively. The laudanosine plasma concentrations were 0.70 (0.12-1.20) microg/mL. The pharmacokinetic variables of cisatracurium are similar to those of patients without organ failure undergoing elective surgery. Plasma laudanosine levels always remained well less that those associated with seizure activity in animal models. Long-term infusion of cisatracurium was not associated with any side effects. Cisatracurium is a suitable muscle relaxant when deep and continuous levels of muscle relaxation are required in patients treated for ARDS. IMPLICATIONS: We studied the pharmacokinetics of cisatracurium in six patients treated for respiratory distress syndrome by continuous muscle relaxation. A deep degree of neuromuscular blockade corresponding to abolition of two responses at the orbicularis oculi to train-of-four stimulation was obtained in all patients. The pharmacokinetic variables observed in these severely ill patients were similar to those of anesthetized patients. No accumulation of laudanosine was seen. Cisatracurium appears to be suitable when continuous muscle relaxation is required in critically ill patients.     

终末期肾病患者顺式阿曲库铵量效关系测定

目的采用单次剂量注射法测定终末期肾病患者顺式阿曲库铵量效关系。方法选取接受肾移植的终末期肾病患者40例,按完全随机方法分为4组,每组10例,对4个剂量组患者按体重注射20、30、40、50μg／kg的顺式阿曲库铵。选取无神经肌肉病变的患者20例作为对照组,给予相同剂量的苯磺酸顺式阿曲库铵。记录每个患者最大抑制效应,并对最大抑制效应进行概率转换,对应的肌松药剂量进行对数转换,用直线回归方法建立顺式阿曲库铵的剂量-反应曲线。结果终末期肾病患者顺式阿曲库铵50％有效剂量（ED50）、75％有效剂量（ED75）、90％有效剂量（ED90）、95％有效剂量ED95分别为30．88、35．65、40．62、43．85μg/kg,无神经肌肉病变患者顺式阿曲库铵ED。ED。ED。ED。分别为35．37、42．22、49．60、54．55μg/kg,终末期肾病患者顺式阿曲库铵ED。明显低于无神经肌肉病变患者ED95（P〈0．01）。结论终末期肾病患者因周围神经病变累及神经肌肉接头可导致对肌松药的敏感性增加。     

Die Wirkung unterschiedlicher Primingdosierungen auf die Pharmakodynamik von Cisatracurium

OBJECTIVE: The aim of the study was to evaluate the effect of two different priming regimen on the onset time of 100 micrograms/kg cisatracurium, when compared to bolus administration. METHODS: 51 patients were randomly assigned and received either a bolus of 100 micrograms/kg cisatracurium, or a priming dose of 10 micrograms/kg cisatracurium followed after 4 min by 90 micrograms/kg cisatracurium, or a priming dose of 15 micrograms/kg cisatracurium followed after 4 min by 85 micrograms/kg cisatracurium. The neuromuscular monitoring was performed using a mechanomyograph (Groningen II Monitor). Anaesthesia was induced with propofol and fentanyl and maintained by continuous infusion of propofol. RESULTS: The priming combination of 15 micrograms/kg cisatracurium followed after 4 min by 85 micrograms/kg cisatracurium produced a statistically significant reduction in the onset time (95% block) (180 +/- 60 s) and time to complete block (210 +/- 48 s), when compared to the bolus group (240 +/- 60 s and 288 +/- 66 s) (p < 0.05). CONCLUSION: Our data indicate that the "priming principle" is an appropriate technique to shorten the onset time of cisatracurium. To achieve a maximum effect the priming combination of 15 micrograms/kg cisatracurium followed after 4 min by 85 micrograms/kg cisatracurium is recommended.     

Intubating conditions using cisatracurium after induction of anaesthesia with thiopentone

We studied tracheal intubation conditions produced by the muscle relaxant, cisatracurium, following induction of anaesthesia with fentanyl (2 μgkg⁻¹) and thiopentone (6 mgkg⁻¹). Sixty patients were randomly assigned to receive cisatracurium in a single bolus dose of either 0.15 or 0.20 mgkg⁻¹. Tracheal intubation was commenced 120 s after injection of the relaxant. The mean (SD) time taken to achieve intubation was significantly shorter in the 0.20 mgkg⁻¹ group (137 (16) s) than the 0.15 mgkg⁻¹ group (149 (12) s; p < 0.05). The intubating conditions were better after the larger dose. Our results suggest that when anaesthesia is induced using thiopentone, a dose of 0.20 mgkg⁻¹ of cisatracurium is recommended to ensure satisfactory intubating conditions.     

Cisatracurium neuromuscular block at the adductor pollicis and the laryngeal adductor muscles in humans

We have compared the dose-response relationship (n = 30) and time course of neuromuscular block (n = 20) of cisatracurium at the laryngeal adductor and the adductor pollicis muscles. ED95 values for cisatracurium were 66.8 (95% confidence interval 61.3-72.3) micrograms kg-1 at the larynx and 45.2 (42.1-48.3) micrograms kg-1 at the adductor pollicis muscle (P < 0.0001). After administration of cisatracurium 0.1 mg kg-1, onset time was 2.7 (2.2-3.2) min at the larynx and 3.9 (3.0- 4.8) min at the adductor pollicis (P < 0.0001). Time to 95% recovery of the first twitch of the TOF was 26.9 (20.1-33.7) min and 45.6 (39.7- 51.5) min, respectively (P < 0.0001). We found that the laryngeal adductors were more resistant to the action of cisatracurium than the adductor pollicis muscle, but onset and recovery were faster at the larynx.      

Pharmacokinetics and pharmacodynamics of cisatracurium in patients undergoing surgery with two hemodilution methods

ObjectiveTo investigate the pharmacokinetics and pharmacodynamics of cisatracurium in patients undergoing surgery under acute normovolemic hemodilution (ANH) and acute hypervolemic hemodilution (AHH).MethodsNinety patients with orthopedic surgery were divided into ANH, AHH and control groups, which received hemodilution by hydroxyethyl starch 130/0.4 transfusion, Voluven transfusion and regular transfusion and infusion during surgery, respectively. Each group was divided into 3 sub-groups, administrated with cisatracurium at dosage of 0.1, 0.2 and 0.3 mg/kg respectively. The changes in plasma protein, pH and electrolytes from the hemodilution beginning to surgery finish were monitored. Before and after cisatracurium administration, the phamocodynamic indicators of muscle relaxant were observed, and the plasma drug concentration was measured.ResultsAfter hemodilution or regular transfusion, all three groups experienced a distinct drop in total plasma protein, albumin and pH. Compared with control group, the plasma concentrations of both K⁺ and Ca^2 + in ANH and AHH groups significantly dropped (P < 0.05), and those in each group after administration of cisatracurium also dropped, compared with before (P < 0.05). After administration with cisatracurium, the onset time of muscle relaxation in AHH group was extended notably, compared with AHH and control groups (P < 0.05), with no distinct difference of residual pharmacodynamics parameters (P > 0.05). In the same hemodilution or regular infusion, with increase of drug dosage, the onset time of muscle relaxation was shortened, and the period of no response to train-of-four stimulation, muscle relaxation blockade duration and action time of muscle relaxation blockade in body were extended (P < 0.05).ConclusionWhen using cisatracurium under AHH, the dosage should be increased appropriately, while it need not be adjusted under ANH.     

Resistance to cisatracurium in a patient with MELAS syndrome

There are conflicting reports on the response of mitochondrial myopathy patients to the neuromuscular blocking drugs, showing either normal response or marked sensitivity. We present a patient with MELAS syndrome who underwent Nissen fundoplication and gastrojejunostomy. Marked resistance to the nondepolarizing muscle relaxant, cisatracurium was observed. The anesthesia management, as well as the various causes of resistance to cisatracurium in this patient are discussed.     

顺阿屈库铵临床药效学分析

目的研究顺阿屈库铵在国人中的临床药效过程。方法选择年龄30～65岁择期全麻手术病人100例。静脉诱导用异丙酚2mg/kg、芬太尼4μg/kg。各项循环监测指标稳定5min后,研究分两部分进行。第一部分将病人随机分成七组,每组10例,Ⅰ组25μg/kg、Ⅱ组30μg/kg、Ⅲ组35μg/kg、Ⅳ组40ug/kg、V组45μg/kg、Ⅵ组     

Comparison of cisatracurium-induced neuromuscular block at the masseter and adductor pollicis muscle

Adequate relaxation of the masseter muscle is important during endotracheal intubation and for the patency of a patient's airway during recovery from anaesthesia. We evaluated onset and recovery from cisatracurium-induced neuromuscular block at the masseter and adductor pollicis muscles. Thirty patients were randomly allocated to receive either 0.1 or 0.15 mg kg(-1) cisatracurium. The evoked response was measured at both muscles using acceleromyography. Onset time was significantly shorter at the masseter muscle than at the adductor pollicis (0.1 mg kg(-1) cisatracurium: 155+/-52 vs. 229+/-44 s; 0.15 mg kg(-1) cisatracurium: 105+/-24 vs. 174+/-35 s). Following 0.1 mg kg(-1) cisatracurium, recovery to a TOF-ratio of 0.7 was faster at the masseter compared to the adductor pollicis (P < 0.05). In the 0.15 mg kg(-1) cisatracurium group recovery of T1 to 75% of control and to a TOF-ratio of 0.7 occurred sooner at the masseter (P < 0.05). We conclude that onset and recovery from cisatracurium neuromuscular block occurs more rapidly at the masseter than at the adductor pollicis. It appears unlikely that residual paralysis is present at the masseter once neuromuscular function at the adductor pollicis has completely recovered.